Stamp pads



I 1953 s. N. RosEnLTHAL 2,847,972

STAMP PADS Filed March 19, 1956 |8 I? MUSLIN SHEE T I f" I6 FELT 4 INKLEvEL l5 GLASS wooL .1 l

FELT

l2 A 4 I25 \IS (IZALFELT INVENTOR. SIDNEY N. ROSENTHAL BY Q fiatATTQRNEYS United tates Patent STAMP PADS Sidney N, Rosenthal, RichmondHill, N. Y. Application March 19, 1956, Serial No. 572,518 1 Qlaim. (Cl.113-265) This application relates to stamping pads and particu' larly toa stamping pad especially designed for highly volatile opaque ink of theclogging type, characterized by rapidity of evaporation of the carrierfluid of the ink with a consequent residue of ink particles which wouldnormally tend to clog the stamping pad.

A stamp pad normally is a somewhat resilient pad saturated with ink andadapted to moisten by contact a rubber stamp or felt nib of a markingpen for inking the stamp or the nib.

A specific object of the present invention is to provide a stamping padespecially designed for ink of the character above described which isdesigned to reduce ink losses as well as hardening of the pad surface.

Further objects of the present invention will best be understood onreference to the appended drawing and the related specification.

In this drawing:

Fig. 1 is an elevation section view of one embodiment of the invention.

Fig. 2 is a top view of the pad with the cover removed.

Fig. 3 illustrates a front view of the closed container.

Referring to the drawings, it will be observed that Fig. 1 shows a stamppad comprising a container having an open top normally closed by afriction fit cover 11 and containing a filler. The filler comprises twoink saturating felt pads 12 and 14. Placed between these pads is a layerof non-absorbent, non-saturating, resilient fibrous material 15, such asglass wool, of which one commercial form known by the trademark Dynelhas been found especially suitable. The ink in the pad fills thecontainer to a level somewhere between the upper and lower surfaces ofthe glass wool layer as indicated by the dotted line 16. The glass woolholds the ink upon its surfaces, but does not provide for capillaryaction.

The lower felt pad 12 is preferably made of doubly ply construction tocontain plies 12A and 12B and each felt layer is formed with an air hole17 normally closed by a felt plug 13 to enhance ink and air circulationthrough the felt pad. The double ply construction provides a spacewithin the lower felt pad for a puddle of ink to gather.

The upper felt pad 14 is considerably harder and is thus of lowerabsorbent nature than the lower felt pad 12.

Covering the upper felt pad 14 is a muslin sheet or layer 22conventional in stamp pad construction.

When a stamp is pressed down on the muslin sheet 22, and thus on theupper pad 14, such pad is moved down into the ink which is at the level16 which is below the normal position of the upper felt pad 14. Theglass wool .16 serves as a spring support for the upper pad 14, ratherthan as a sponge, and normally maintains the upper pad 14 out of contactwith the ink at level 16, and thus minimizes the saturation of the pad14 and the consequent loss by evaporation of the fluid of such ink.

In other words, the glass wool 16 functions as if it were a coil springto maintain pad 14 out of contact with the ink, but to permit pad 14 tobe moved down by stamping pressure to become saturated with the ink forwetting the pen nib or the stamp applied to the muslin 22 The glass woollayer 16 also functions to prevent splashing of the ink between the padsand to break up the flow of ink in the up and down movement of the pad14 and thus to prevent splashing.

Because the lower felt pad 12 is more absorbent than the upper felt pad14, ink tends to flow down from the space filled by the glass wool,rather than up. Thus, when pressure is applied to the upper pad 14, theink adhering to the surfaces of the glass fibers is squeezed upward intothe upper pad 14 and downwardly into the lower pad 12. Therefore, theupper pad does not become over-saturated and consequently, does notevaporate what would otherwise be excess ink in the upper pad.

This invention may be further developed within the scope of thefollowing claim. Accordingly, it is desired that the foregoingdescription be read as illustrating one operative embodiment of myinvention, rather than in a strictly limiting sense.

Now having described the stamp pad hereof, reference should be had tothe following claim.

I claim:

A stamp pad for use with highly volatile inks comprising a containerhaving an open top and two ink saturant felt pads at the bottom and topthereof; and a pad of glass wool between said felt pads; said glass woolpad being in contact with the felt pads and filling the space betweenthem and supporting the upper felt pad; said container being adapted tocontain ink at a level beneath the normal position of the top felt pad;the top felt pad being compressible into the container against the glasswool pad to reach the ink level and being maintained in its normalposition above the ink level by the glass wool pad.

References Cited in the file of this patent UNITED STATES PATENTS204,726 Hammond June 11, 1878 340,761 Chamberlain Apr. 27, 18861,538,241 Colville May 19, 1925 2,152,682 Dwofsky Apr. 4, 1939 2,375,178Ruben May 1, 1945

